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Interesting 348 alternator problem

Discussion in 'Technical Q&A' started by rivee, Jun 2, 2005.

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  1. rivee

    rivee F1 Rookie

    Jan 20, 2002
    3,731
    Nowhere important, USA
    Full Name:
    John
    #1 rivee, Jun 2, 2005
    I recently had the battery light come on in my 348. So I checked the wiring for possible loose or corroded connections and determined it was the alternator. I took it off and took it to my alternator guy. He ran a quick test and said it appeared fine, but would keep it for awhile just to make sure.

    When I contacted him a couple of hours later he said it had run for awhile and turned out it was bad after all.

    It is a Delco alternator. Not sure if it's the original one though.

    I told him to fix whatever the problem was and to rewind it to 140 amps, since it was only 105 amps.

    When I went to pick it up, he said it had an unusual problem. Apparently, when the unit was manufactured they put the wrong spacer between the rotor and the end bearing, so the brushes weren't running totally on the commentator.

    He said they used two different end bearings on these alternators, each with a different spacer, and mine was the larger bearing which took the thinner spacer.

    He also said that the unit was made with inferior parts, such as the rectifiers silver contacts instead of copper leads and etc...

    I was just wondering if this was the cause for so many 348 Delco alt. failures in the past?

    Now all is well with my new 140 amp alternator.
     
  2. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,055
    USA
    #2 f355spider, Jun 2, 2005
    Not sure about that...the biggest problem is voltage regulation. They will initially test fine...but if run for a while and get hot, the voltage will taper off, causing a dead battery. My friend had this exact problem, took it out and tested fine. He knew it was not, and took it else where. Tested for an extended period, and "bingo" voltage dropped off. His was the "upgraded" nippondenso, used in the later 348's.
     
  3. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    #3 parkerfe, Jun 2, 2005
    A bad alternator can give you strange symptoms. On my BB512i last summer I noted the water temp running a little hotter than normal, 95c to 100c instead of the 90c it had been running. All three fans were turning and the themostat was opening so I at first though I had some type of major engine problem. Well, it turned out to be bad alternators that were not putting out enough current to turn the fans at full speed. I had both alternators rebuilt for $150 each and the fans started spinning noticiably faster and the water temp went back down to 90c. But, who would have thought that a symptom of a bad alternator can be your water temp top run hotter than normal?
     
  4. dbcooper

    dbcooper Formula Junior

    Feb 7, 2005
    281
    Costa Mesa,Ca.
    Full Name:
    Tim Romero
    #4 dbcooper, Jun 3, 2005
    I had a customers alt rebuilt and test drove it and all seemed well.customer returned 5 minutes later and said"hey ,the light comes on!" so we went for a drive and yes the light did come on at about 9,000 r.p.m.(at least it sounded like 9,000rpm) He drives his car just a wee bit hard and fast.(faster than I will test drive them).so,i pulled and returned the alt to the builder and he replaced rectifier/brush/regulator assy and i reinstalled it and at approx 9,000r.p.m.or so, the lite came on again.alternator was a nippon denso unit and I took it apart and found rebuilder was using substandard chinese parts.I ordered and replaced with O.E> nippondippo parts and no more light.substandard parts work ok for cars that dont see high r.p.m's Like an old Hyundai
     
  5. russell

    russell Karting

    Mar 2, 2005
    217
    sacramento
    Full Name:
    russell
    #5 russell, Jun 3, 2005
    we have a brand new one from ferrari in stock and will sell it for 650 bucks.
    well over 1k usually at dealer
    email [email protected]
     
  6. rivee

    rivee F1 Rookie

    Jan 20, 2002
    3,731
    Nowhere important, USA
    Full Name:
    John
    #6 rivee, Jun 3, 2005
    After all said and done, I have an alternator with new regulator, rectifier, 140 amp windings, and bearings, all quality parts.

    Cost?

    Alt.= $185.00
    My labor= 3 hrs@ 1.84/hr=$5.52
    Parts cleaner=$4.87
    New alt. belt=$18.00
    Alcoholic beverages, before, during, and after work completed=$22.94



    Total=$236.33
     
  7. russell

    russell Karting

    Mar 2, 2005
    217
    sacramento
    Full Name:
    russell
    #7 russell, Jun 4, 2005
    way to go..
     

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